Specific Characteristics Of Direct Current

The movement of charged particles or atoms through a conductor or space is called current. The S.I unit is Ampere.

Current is generally of two types-

1. Direct Current is a type of current that flows or moves only in one direction.
2. Alternating Current changes its direction or flow of current over time. 

In this article, we are going to study direct current.

DC

DC means direct current. A direct current is a type of current that flows or moves only in one single direction. Electrons move from a negative direction towards a positive direction.

Thomas Edison discovered direct current in the late 19th century. 

The current that flows in products that run on batteries or cells is an example of direct current. Its frequency remains zero. DC plots a pure sine wave. 

By using an inverter, we can convert direct current and alternating current. We can also transform AC into DC by a rectifier.

As direct current is constant, its symbol is a straight line. 

Source of DC – generators and battery. 

Applications of DC 

The applications of DC are: 

•  Batteries, rechargeable and non-rechargeable, both supply DC

•  Solar panels, solar power plants, mobiles, computers
•  AC, fans, lights, sockets, flashlights, flatscreen TVs, electric vehicles and radios use direct current

The characteristics of direct current

• It is unidirectional. 
• It only moves in a forward direction, from positive to negative and is constant in time.
• As the direction flow remains the same, it provides constant voltage.
• The frequency is zero or it often has no frequency as it does not change direction. 
• It is produced from batteries and DC generators. 
• It has constant polarity.
• It avoids the occurrence of inductance and capacitance.
• The power factor of direct current is 1.
• Types of DC – pure direct current and pulsating direct current. 
• At each instant of time, pure DC has a constant magnitude, a DC has a variable magnitude. 
• The loss of electrical energy is very low in an HVDC (high voltage direct current) transmission system. 
• It connects with the resistive type of load. 

 DC Circuits

 A closed path in which direct current flows is called DC circuit. 

It is of two types; series circuit and parallel circuit. 

In a series DC circuit, all the resistors are connected end to end so that the same current flows through all of them. 

In a parallel DC circuit, all the resistors are connected to a common voltage supply. There should be two or more resistances that are not connected in series in a parallel circuit. 

Merits of DC

• It provides high efficiency and reliability. 
• It provides better safety. 
• It does not cause power problems. 
• It is more energy-efficient because it has constant polarity and magnitude. 
• It is more eco-friendly as it can be generated from renewable sources. 
• Almost all the household applicants depend on DC supply as DC circuits are noise-free and have low power loss. 
• It has a low installation cost and is stable. 
• It can store electrical energy very efficiently and easily. 
• DC power transmission and distribution are comparatively less expensive. 
• It needs less insulation as potential stress is less on conductors in DC transmission. 
• DC electric motor speed can be changed very easily. 

Demerits of DC

• DC can be pretty complex.
• Because of the commutation problems, it is sometimes challenging to generate a high voltage.
• DC switches and circuit breakers are expensive.
• We can not step up or step down the DC voltage amplitude. 
• It has heating problems. 
• It has a high cost of transmission as it requires different types of equipment like rectifiers and inverters. 
• Direct current is comparatively dangerous. 
• It is sometimes expensive to change the voltage of the current. 

Conclusion

A direct current is a type of current that flows or moves only in one single direction. In this article, we learnt about direct current. We also discussed the specific characteristics of dc current. We studied the merits and demerits of DC. This is a very crucial topic for physics students and students appearing in board exams. This topic is also helpful for students or aspirants appearing in IIT/JEE/NEET exams.